Hermetically sealed electrolytic cell



Feb. 18, 1969 L w. E. GILBERT 3,428,869

HERMETICALLY SEALED ELECTROLYTIC CELL Filed Oct. 12, 1966 Sheet of 2 Ftgl. 2O

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HERMETICALLY SEALED ELECTROLYTIC CELL Filed Oct. 12, 1966 Sheet 2 of 2 INVENTOR. WILL/AM EKG/8527 6M, 6M, QMAQ M A T TOR/VEYS United States Patent 3,428 869 HERMETICALLY SEALED ELECTROLYTIC CELL William E. Gilbert, Grand Island, N.Y., assignor to Spaulding Fibre Company, Inc., Tonawanda, N.Y. Filed Oct. 12, 1966, Ser. No. 586,202 US. Cl. 317-230 4 Claims Int. -Cl. H01g 9/08 ABSTRACT OF THE DISCLOSURE An electrolytic cell has container laminated with a shoulder on the wall near the open end. A laminated seal cap comprises two substantially rigid insulative discs with a sandwich layer of cold-flow insulative caulking material between them. The seal cap fits into the open end of the container against the shoulder and the terminals of the cell project through it. A marginal lip around the end of the container is spun over against the edge of the cap, and the pressure thus exerted laterally expands the caulking material into sealing engagement with the wall of the container and around terminals.

This invention relates to electrolytic cells, and more particularly to the end closure and sealing means therefor; such as for example in connection with the construe tion of electrical capacitors, power cells, rectifiers or the like.

A cell of the type above referred to typically comprises a tubular casing with an integral bottom end wall which is hermetically sealed at its other end subsequent to installation of the functional contents of the cell, by means of a sealing-closure device from which the electric terminals extend. Subsequent to this assembly the top edge of the casing is spun over the marginal edge of the closure device to mechanically retain it in position. A large variety of arrangements for sealing the closure device relative to the casing and the terminals relative to the closure plate have been previously designed and employed, but without entirely satisfactory results.

It is a primary object of this invention to provide in a cell as aforesaid an improved combination end closure and terminal sealing construction.

Another object is to provide improved means for sealing the end closure member relative to the casing wall member and relative to the electric lead and/ or terminal devices extending therethrough.

Another object is to provide an improved sealing-closure device as aforesaid which is of simple construction and not expensive; yet which functions with improved efiicacy.

Other objects and advantages of the invention will appear from the following specification and the accompanying drawing wherein:

FIG. 1 is a fragmentary sectional view on enlarged scale, through a typical capacitor embodying an end closure and sealing construction of the present invention;

FIG. 2 is a reduced scale top perspective view of the combination closure and sealing device of FIG. 1;

FIG. 3 is a fragmentary diagrammatic view illustrating a subassembly step in the construction of a modified form of the device;

FIG. 4 corresponds to FIG. 3 and shows another subassembly step thereof; and

FIG. 5 corresponds to FIG. 1 but shows the modified form of the construction attained by the assembly system of FIGS. 3, 4.

As shown by way of example in the drawing herewith, an electrolytic cell embodying the invention may be constructed to comprise a generally cylindrically shaped casing formed of sheet metal or the like. The casing portion 10 may be initially formed open at both ends or closed at its bottom end by an integral end wall (not shown), as may be preferred. In any case it will be open at one end (referred to as the upper end herein) to accommodate insertion of the electrodes or the rolled capacitor subassemply therein, such as is indicated at 14. Leads or risers as indicated at 16 extend upwardly from the subassembly 14 for electrical connections as indicated at 18 with corresponding terminals 20. Note that the terminals 20 typically terminate in right angle flange portions 24 at their lower ends for embedment in the end closure and sealing device; whereby to anchor the terminal pieces in the unit and thus shield the electrical connections against mechanical disruption.

The combination end closure and sealing device of the present invention is constructed as shown in FIGS. 1, 2, of the drawing herewith to comprise a sandwich-shaped assembly as indicated generally at 25. This structure comprises a base plate 26 formed of resin-bonded laminate, fiber board, or the like; a second layer of a non-corrosive cold-flow caulking material such as uncured camelback rubber 28 or a substitute therefor having suitable coldflow properties, as will be explained hereinafter; a next layer of an elastomer material such as cured rubber as indicated at 30; and a top layer of resin-bonded laminate material as indicated at 32.

The parts are appropriately punched to provide apertures as indicated at 36 (FIG. 2) through which the risers 16 and terminals 20 will snugly slip-fit when the parts are brought into assembled relation as shown in FIG. 1. The electrical interconnections between the risers and the terminals may then of course be firmly established by any suitable means such as by mechanically crimping the terminal fins 38 upon the risers, or by soldering the interconnections; or by any combinations thereof. The unit comprising the subassembly 14 and the sealingclosure 25 is then lowered into the container 10 until the inner rim portion of the unit 25 seats against an inwardly extending flange portion 39 of the container. A retaining washer 40 is then slip-fitted into position to ride upon the top rim portion of the closure unit, whereupon the upper edge of the container may spun inwardly and downwardly as illustrated at 12, thereby completing the mechanical retention of the closure unit in container-sealing position.

As shown in FIGS. 3-5, the combination closure and sealing device may be alternatively fabricated in the form of a pair subassemblies. For example, the top layers 30, 32, may be initially assembled as a unit while the lower layers 26, 28, are initially assembled as a separate unit. These units are then punched to provide close fitting apertures through which capacitor risers and the terminals will be slip-fitted. Note that the terminals 20 may then be slip-fitted upwardly through the top subassembly unit until the bottom flange portions 24 thereof bear upwardly against the bottom of the elastomer plate 30. The lower unit is then slip-fitted downwardly upon the risers 16 to the operative position as shown in the drawing. The upper unit, carrying the terminals 20, is then slip-fitted downwardly upon the risers 16 until the two units are in mating assembly.

The electrical connections between the risers and the terminals are then perfected as explained hereinabove. The device is then transported to the final assembly station at which the top edge of the container 12 is spun inwardly and down into closure locking position as shown at FIG. 5 in the drawing herewith. Obviously, any other mode of assembly may be employed if preferred, other than the assembly processes described hereinabove; the objective being to attain a firm relative assembly of the closure parts and of the closure device relative to the container.

To facilitate handling of the subassembly parts incidental to transport to the final assembly operation, the camelback layer may be sprayed or otherwise thinly coated With a film of a release agent, such as a polyethylene solution which will operate to prevent the camelback parts from undesirably adhering to adjacent articles so as to be difiicult to handle during the subassembly and final assembly processes.

It is a particular feature of the closure-seal device of the invention that when in operative position the laminate plates 26, 32, receive the mechanical loadings on the unit and compress therebetween the elastomer and camelback layers 30, 2 8. Hence, the materials of the latter are induced to flow into firmly sealing relation with the container Wall and also into firmly sealing relation with the risers and the terminal devices. Pressures developing internally of the cell will thus be retained by reason of the ability of the camelback material to creep if necessary into any minor void as may occur within the assembly due to parts dimensional irregularities.

However, the elastomer layer 30 restrains the camelback material from extruding out of the assembly while at the same time providing a means allowing the pressures to vent in the event they build up to explosive magnitude.

Thus, it will be appreciated that although the construction of the invention involves only the use of relatively inexpensive parts which are easily assembled and mounted in the container, the device functions to amply guard against leakage of electrolyte from the container under normal operative conditions. It will of course also be understood that although only a few forms of the invention have been illustrated and described hereinabove, various changes may be made therein without departing from the 1. In an electrolytic cell of the type comprising a container and a sealing closure fitting into an end opening thereof and having terminal devices extending therethrough, the improvement comprising:

said sealing-closure consisting of a sandwich-like unit slip-fitted into said container opening against a supporting shoulder portion thereof and held in place by mechanical pressure applying means, said unit comprising a base plate forming a substantially rigid backing, a body of cold flow caulking-type material layered upon said base plate, a cover sheet of elastomeric material disposed above said body of caulking-type material, and a top cover plate forming a substantially rigid backing in cooperation with said base plate to cause said caulking-type material to be expelled into sealing contact with said container.

2. A sealing device as set forth in claim 1 wherein said caulking material comprises an uncured camelback rubber.

3. A device as set forth in claim 2 wherein said elastomeric material comprises cured rubber.

4. A device as set forth in claim 1 wherein said terminal devices include laterally flanged foot portions embedded within said caulking and elastomeric materials.

References Cited UNITED STATES PATENTS 2,758,149 8/1956 Brennan 317-230 3,248,613 4/1966 Griffin et al. 317 -23o 3,335,335 8/1967 Perkins 317-230 JAMES D. KALLAM, Primary Examiner.

US. Cl. X.R.

spirit of the invention or the scope of the following claims. 174 52;

I claim: 

